This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2024 project "Grey Nurse Shark aggregations". For specific data outputs from this project, please see child records associated with this metadata. -------------------- The grey nurse shark (Carcharias taurus) has been protected in Australian Commonwealth waters since 1996. Although historically distributed across southern Australia, in October 2001 the grey nurse shark was listed as two separate populations with different protection listings under the EPBC Act of 1999: Critically Endangered in eastern Australia, and Vulnerable in Western Australia. Grey nurse sharks (GNS) tend to aggregate at specific sites along migration routes. There are currently 19 identified key aggregation sites along the eastern seaboard. Recent observations indicate that this definition requires revision to account for factors such as seasonal movements and to be applicable to the Western Australian population. This project aims to collate existing information on key aggregation sites and ‘new’ sites where GNS have been found to gather (both in eastern and western Australia). This information will be used to refine the definition of key aggregation site and develop criteria to allow assessment of new sites. This project will also investigate potential sites in Victoria where the least amount of information is available. Outputs • Spatial information on key Grey Nurse Shark aggregation sites [dataset] • Final project report [written]

This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2024 project "Enhancing monitoring approaches to evaluate the abundance, life history and critical habitats of the endangered Australian sea lion". For specific data outputs from this project, please see child records associated with this metadata. -------------------- The Australian sea lion (ASL; Neophoca cinerea) is Australia’s only endemic pinniped. Populations have declined by more than 60% over the last 40 years to extremely low levels, leading to its endangered status. Known threats to the species include fisheries bycatch, disease, pollution, entanglement in marine debris, and climate change. Improving our understanding of the species’ abundance, life history and critical habitats is essential for evaluating these threats and guiding recovery actions but is challenging due to the species’ unique life-history and breeding biology, longevity, demersal foraging behaviour and occupancy of remote breeding habitat. This project aims to improve the monitoring and inform the management of Australian sea lions by developing cost-effective methods for acquiring abundance data from under-surveyed regions impacted by anthropogenic pressures. To do so, it will: • Apply drones to enhance monitoring at suitable breeding and haul-out sites • Develop efficient techniques to process and analyse demographic data so that survival and reproductive success estimates from a microchipped population at Seal Bay can be routinely updated; and • Continue to deploy underwater cameras on sea lions to identify and understand critical habitats and risks. Findings from these activities will underpin the National Recovery Team conservation efforts, in line with the Australian Government's Threatened Species Action Plan and Healthy Country plans. Outputs • Qualitative and qualitative spatial assessments of breeding sites from helicopter surveys in Recherche Archipelago [dataset] • Drone-collected photogrammetry, FLIR, thermal imaging and LiDAR data [dataset] • Demographic results from analysis of Seal Bay microchipping program [dataset] • Tracking data from sea lion-deployed tags: location, depth, time, temperature, light, acceleration [dataset] • Timestamped video footage from sea lion-deployed cameras [dataset] • Short non-technical summaries to distil the key findings and take-home messages [written] • Final project report [written]

This aim of this project is to identify and map critical habitats for Australian sea lions (Neophoca cinerea) to assess the ecological value of different habitats for sea lions and identify risks to their populations. Through this project we collected animal-borne video, GPS, time-depth and accelerometer/magnetometer data from eight adult female Australian sea lions from Olive Island (n=4) on the western Eyre Peninsula and Seal Bay (n=4) on Kangaroo Island in South Australia. Sea lions were instrumented with animal-borne cameras with integrated accelerometers/magnetometers (CATS Cam, 135 x 96 x 40 mm, 400 g) and satellite-linked GPS loggers with integrated time-depth recorders (SPLASH-10, Wildlife Computers, 100 x 65 x 32 mm, 200 g). Sea lions were sedated and anaesthetised and bio-logging instruments were glued to the pelage on the dorsal midline. Bio-logging instruments were recovered after a single foraging trip (~1-6 days). Populations of the endangered Australian sea lion have declined by >60% over the last 40 years. Australian sea lion populations show a marked uneven distribution in abundance across their range, which suggests that localised risk profiles from threats vary at small spatial scales. Fine scale differences in habitat-use are thought to underpin these differences. However, knowledge of the habitats that are critical to Australian sea lions is poor and their vulnerability to human impacts and threats at the fine-scale is not well understood. The data collected in this project provides fundamental information on critical benthic habitats for Australian sea lions, the differences in foraging behaviour of individual sea lions and their prey preferences. The information collected under this project improves our understanding of threats to sea lion populations and will support future conservation actions to recover the species.